condition mean min max ZT0-3 2.57272555825 2.3209639795 2.824487137 ZT4-7 3.544941325 3.310653516 3.779229134 ZT8-11 5.64392744 4.487309686 6.800545194 ZT12-15 4.8179063595 4.476992426 5.158820293 ZT16-19 4.505860172166667 4.330843823333334 4.680876521 ZT20-23 5.5477810695 5.148833394 5.946728745